CVE-2026-1513 identifies a cross-site scripting (XSS) vulnerability in the billboard.js JavaScript charting library developed by NAVER. The vulnerability exists in versions prior to 3.18.0 due to improper neutralization of input during the binding of chart options. Specifically, the library fails to adequately sanitize user-supplied data that is incorporated into the chart configuration, which can be manipulated by an attacker to inject malicious JavaScript code. When a vulnerable application uses billboard.js to render charts with attacker-controlled input, the malicious script executes in the context of the victim's browser, potentially leading to theft of sensitive information such as cookies or tokens, session hijacking, or unauthorized actions on behalf of the user. The CVSS v3.1 score of 6.1 reflects a medium severity, with an attack vector over the network (AV:N), low attack complexity (AC:L), no privileges required (PR:N), but requiring user interaction (UI:R). The scope is changed (S:C), indicating that exploitation affects resources beyond the vulnerable component. Confidentiality and integrity impacts are low, while availability is unaffected. No known exploits have been reported in the wild, but the vulnerability poses a risk to any web application integrating vulnerable versions of billboard.js. The lack of a patch link suggests that users should upgrade to version 3.18.0 or later where the issue is resolved. Developers should also implement input validation and output encoding to mitigate injection risks. Additionally, applying Content Security Policy (CSP) headers can reduce the impact of potential XSS attacks by restricting script execution sources.

For European organizations, this vulnerability can lead to unauthorized execution of malicious scripts within users’ browsers, compromising confidentiality and integrity of data. Attackers could steal session cookies, perform actions on behalf of users, or redirect users to malicious sites. This is particularly concerning for organizations that rely on billboard.js for data visualization in customer-facing or internal web applications. The medium severity indicates a moderate risk, but the widespread use of JavaScript libraries in Europe’s digital economy means the potential attack surface is significant. Exploitation could disrupt trust in affected services, lead to data breaches, and cause regulatory compliance issues under GDPR if personal data is compromised. The requirement for user interaction limits automated exploitation but does not eliminate risk, especially in phishing or social engineering scenarios. The absence of known exploits suggests a window for proactive mitigation before active attacks emerge.

1. Upgrade all instances of billboard.js to version 3.18.0 or later where the vulnerability is fixed. 2. Implement strict input validation and sanitization on all user-supplied data before it is passed to billboard.js to prevent injection of malicious scripts. 3. Apply Content Security Policy (CSP) headers to restrict the execution of untrusted scripts and reduce the impact of potential XSS attacks. 4. Conduct code reviews and security testing focusing on client-side libraries and their integration points. 5. Educate developers on secure coding practices related to JavaScript and third-party libraries. 6. Monitor web application logs for unusual activity or signs of attempted exploitation. 7. If upgrading immediately is not feasible, consider temporarily disabling or limiting features that accept user input for chart options. 8. Use web application firewalls (WAFs) with rules to detect and block XSS payloads targeting billboard.js.